The problem confronted by the electronic fabrication industry is to dissolve bi-layer photoresist for rework processes, which need to be done at less than 65° C./3 minutes using single wafer tool process. For the conventional photoresist strippers, the problem can be resolved at high operation temperatures (>75° C.) and long process times (over 10 minutes). For some conventional strippers, photoresist is removed by lifting-off rather than dissolving. Non-dissolved or partially dissolved photoresist can clog the filter in the recirculation tool or re-deposit on the wafer, either of which is not acceptable by current semiconductor customers.
Therefore, the conventional photoresist strippers are not suitable candidates for this application of dissolving bi-layer photoresist for rework processes.
The present invention overcomes the shortcomings of the prior art as will be set forth below with several preferred embodiments.